Ann: Wizard Lake Well Frac Commences, page-9

This is of course the truth and a very valid point. Oil (and gas) accumulations are generally in the vicinity of plate boundaries.  It follows that plate movements would continually result in the shifting of fluids and gasses in porous or fractured rock media. 

My only reservation to fracking relates to the competence of operators and level of information used to perform these operations.  If done and monitored properly, the risk of environmental release is minimised.  If, (as tends to be the case when people try to cut costs) cowboys take over, then it all goes to hell. The regulators of course have to consider this and they understandably implement measures to mitigate the potential for this to occur.